Rocker arm



F. J. JONES ROCKER ARM May 4, 193 7.

Filed July 14, 1934 INVENTOR.

m B. W

ATTORNEY-D Patented May 4, 1937 UNITED STATES PATENT OFFICE.

2,079,254 ROCKER ARM Application July 14, 1934, Serial No. 735,132

3 Claims. (01. 74-559) My invention relates to rocker arms for attachment to the pistonrod in horizontal pumping engines to communicate an oscillating motion to the rock shaft to which the valve rod links are operatively connected.

In ordinary horizontal pumps having a steam end and a pump end the piston rod connecting the engine piston with the pump piston has connected therewith arocker arm which is employed to communicate a rocking motion to a shaft which in turn communicates a reciprocating motion to the valve rod link. As this rocker arm' swings on the arc of a circle with the rock shaft as a center the arm necessarily must be capable of longitudinal movement to accommodate this swinging movement. In the rocker arms now ordinarily employed the longitudinal movement along the rocker arm is accommodated by the connection between the arm and the piston rod.

2 This type of connection is liable to very. rapid.

wear with the result that the movement of the rocker arm is not continuously accurate and the valves upon the steam end of the pump are not moved with accuracy after the wearing takes 25 place.

It is an object of my invention to provide a rocker arm having provision for longitudinal extension of the arm in operation in such manner that the minimum of wear occurs and in which 30 the wear when it doesoccur will have a minimum of effect upon the oscillation of the rock shaft.

I further desire to provide a rocker arm which is of simple construction and easily assembled and which may be manufactured at an econom ical cost to the user.

In the drawing herewith, Fig. 1 shows aside View partly in section of my improved rocker arm connected with the piston rod.

Fig. 2 is a side elevation of a steam-operated 40 pump in which my rocker. arm is employed.

Fig. 3 is a side view taken in section on the line 3-3 of Fig. 1. V

Fig. 4 is a side elevation of a slightly modified form of rocker arm which embodies the invention.

45 With reference to Fig. 2 I have shown a somewhat diagrammatic side elevation of a steam-operated pump of ordinary construction to which my invention. may be applied. In this view it will be noted that there is a steam cylinder I having 50 at. its upper side a valve chamber 2 and as these features are common ones now well understood they need not be further described. The piston operating within the cylinder l is connected by i a piston rod 3 with the pump piston working in 55 the cylinder 4. This is all common construction.

The rocker arm which forms the subject matter of this invention is shown as comprising a lower section 5 and an upper section 6 telescoping within the section 5. The section 5 is a sleeve having a cylindrical recess or socket l therein to telescopically receive the upper section 6 which is slidable therein. The lower end of the section 5 is provided with a bearing opening 8 to receive a pin 9, as will be noted from Fig. 3. The lower end of the section 5 is slotted to receive a lug l0 upon a coupling member H. The pin 9 extends transversely through the lower end of the section 5 and the lug l0 making a pivotal connection.

The upper section 6 has a collar l8 formed integral therewith and adapted to fit about the rock shaft H! to which it is keyed bythe key or spline l3. It will thus be obvious that as the rocker arm is swung laterally due to the reciprocation of the piston rod the rocking or oscillating motion will be delivered to the shaft [2. The collar I8 is detachable from the shaft and may be clamped securely thereon by means of a through bolt l4 extending through projecting lugs l5 on the collar.

It is to be understood of course that the rock shaft l2 has a downwardly extending arm I6 thereon which is connected to the valve link rod I! in the usual manner.

The coupling member I I previously referred to has a threaded connection with the two sections of the piston rod 3.

It will be obvious from this disclosure that as the piston rod is reciprocated in the operation of the pump the rocker arm is free to swing and in so doing the arm will be lengthened and shortened between the two positions shown in full lines and in dotted lines in Fig. 1. The upper section 6 will telescope freely in the lower section of the rocker arm and as this telescopic connection may be freely lubricated very little wear will occur. It is obvious also that this arm may be employed until material wear takes place before any material change in the amount of rocking movement communicated to the shaft l2 will be noticeable. The rocker arm has the advantage therefore of wearing very slowly and when wear does occur very little effect upon the'movement of the rocker arm will be noted.

In Fig. 4 I have shown a somewhat different embodiment of the invention in which the lower section 5' of the rod has connection with the coupling sleeve I l in the same manner as in the first embodiment. The upper portion of this section, however, is formed at l9 with a longitudinal slot or opening 20.

Within this slot or opening is slidable an ovalshaped block ill at the upper end of which is an opening 22 to receive the end of the rock shaft l2. As will be seen from the drawing, the block 2| has a slight flange 23 on its outer margin which overlies the side of the opening 20 in the lower portion of the arm and tends to hold the two portions of the arm in connection with each other.

In operating this form of the invention the swinging of the lower portion of the rocker arm during the operation of the pump will be accommodated by the sliding of the block 2| within the opening 20 in an obvious manner so that the advantages obtained in the first embodiment will be closely approximated. In either of these forms of the invention the wear between the parts will have very little efiect upon the extent of the rocking motion communicated through the arm to the rock shaft l2.

What is claimed as new is:

1. In combination with a slush pump having a pump end and a power end including a power control valve, a piston rod extending between said ends, a coupling on said rod, a pivot pin carried thereby, a yoke pivoted to said pin, an elongated opening therein, an elongated block in said opening, a shaft fixed to one end of said block transversely thereof, a support for said shaft, an arm on said shaft, and a connection thereon extending to the power control valve.

2. In a device of the class described, the combination with a slush pump including a pump end and a power end including a power control valve operated by reciprocation of a valve rod, and including a piston rod extending between said ends, of a rock shaft located at right angles to the piston rod, a crank arm extending between the shaft and the valve rod for reciprocating the. rod upon rocking movement of the shaft, a first perpendicularly extending element keyed to the shaft, a second perpendicularly extending element pivotally connecting said piston rod upon an axis parallel with the rock shaft, and a sliding connection between the elements permitting them relative longitudinal movement.

3. In combination with a slush pump having a pump and a power end and including a power control valve, a piston rod extending between said ends, a coupling on said rod, a pivot pin carried thereby, a yoke pivoted on said pin and having a shank, a bracket on said pump, a journalled rock-shaft journalled in said bracket, a perpendicularly extending element fixed thereto, a slidable connection between said element and said yoke shank, an arm on the shaft, and a valve rod connection thereon extending to the power control valve.

FLOYD J. JONES. 

